The Project Pad

OK first of all, that clatter you are describing at MIDRANGE and HIGH BOOST is probably detonation! Torque peak (midrange and high boost) is when knock/det is most common. You should see if it goes away when you pull timing in that range. This also worries me that you could have a timing issue.


Alright, I'm starting with the N75 unplugged log. This is very minor, but my first thought was that you *might* be able to gain a little spool by changing "Boost valve OFF below this pressure" to something more like 105 kPa. See what the MAP sensor reads with the car off, and set it just above that. It might not help, but with a quick spooling little turbo like the k24, it may help make sure the wastegate stays closed when you want it to.

Your fuel tune really needs some help. You can see a spike right after you stab the throttle. One important thing to know about tuning fuel is that your wideband sensor will have some lag time associated with it. From the beginning of the increase in throttle position to the top of that spike in lambda is the partially due to lag in the wideband. It looks like about 0.25 s in this case. If you look at the end of the pull where you go to 0% throttle position, you will also see the associated lag in the wideband (time until it goes into lean decel). It looks to be around 0.5 s there. That's probably the true value of the lag in the sensor.

That spike after you stab the throttle means you need to add some acceleration enrichment (Tuning > Acceleration dTPS dMAP Enrichment). I would add some enrichment in the 40 and 160 dTPS range.

After the lean spike, you can see that it goes much richer (or less lean). That is from hitting the "hump" in your fuel map. In fact, this part of the map is actually tuned pretty well. 0.9 lambda is fine for that region. After getting over that hump in VE values, the engine goes very lean. This is dangerously lean and you really should have backed off of the throttle at this point. If you see >0.9 for long periods of time while tuning under 200 kPa, then you need to stop and add some fuel. I'm not sure what's going on with that random 129, 72, and 48 in the lower part of the map. The map should have only smooth transitions. Other than that, I don't have any more comments on this log. You did much better with the throttle control on this one and good job at keeping it at low RPM until you had to lift off.


On to the other log you posted.

Try harder to hold throttle at 100%. Use it like an ON/OFF switch for logging. If you could start at 2000 RPM with 0 throttle and just stab it and hold it until whenever you have to let off, that'd be awesome. The same goes for getting off of the throttle.

It looks like that turbo is spooling a bit slower than it should be in this log, especially considering that the N75 is working here and calling for 100% duty cycle as the turbo spools (as it should be). It takes 1000 RPM to increase 10 psi in this log... either I am remembering the k24 too fondly, or something isn't right.

Now, why is the boost dropping? Well, part of it is definitely attributable to the boost duty cycle dropping shortly after reaching the target boost. The requested duty cycle is dropping because of your "Boost refDC vs. RPM Curve." Increase those values until you arrive at a boost level you are happy with.

The good news is that your VE table is much better tuned at this boost range! Go you! I wouldn't change much to it here. The main thing to do is get your boost control down and figure out if that turbo is spooling too late. It is easy to see it choking out on the high end, but we can fix that with better boost control. For now, use the open loop method (tune that RPM vs boost table). After you lean a little about close loop tuning, we will get it to hold 20 psi in a straight line across the map to at least 6500 RPM... that is... if your fuel injectors can handle it (they probably wont).

Thanks brother I know its no small feat helping someone tune their car over the internet so know that I appreciate it. Go Me! haha Yes but that good VE tuning is mostly due to me being able to throw together a good original VE table using Phil's and figuring out ratios based on the fact that he and I have totally different req_fuel values. His configs have been a tremendous help and guestimating a lot of things for my config. Also, Id like to publicly thank autotune . Do you think I should make the 20 psi my main goal instead of 24 tapering to 19 like my IA ecu did? I have been striving to reach the level of tune the IA chips provided with hopes of surpassing that tune using the meth injection and more ignition advance. Perhaps I can make just as much power with 20 psi and meth (lower MAT/110 octane equivalence) and ignition advance though? I added 5 to both the 40 and 160 dTPS areas. Will see how that goes. Those errant values in the VE table were just mess ups from the auto tune feature that I planned to fix at some point. 101 - 103 is the going range for atmosphere when the car is off so I went to 105 kPa for the "off below this pressure" feature for the N75. Will take the logs soon but I have no gas money until 034 refunds my ring gear and too long crank bolts RMA theyre getting tomorrow. Need money for food more than gas lol.

One last thing, what the heck if my refDC values are 100% and I'm still not reaching the boost goal at higher RPMs? Havent logged it yet obviously but for instance I changed the refDC value for 6k rpms on that table to 100% to see if things move upward there. It was close to there already previously.

88a5tq wrote:Thanks brother I know its no small feat helping someone tune their car over the internet so know that I appreciate it. Go Me! haha Yes but that good VE tuning is mostly due to me being able to throw together a good original VE table using Phil's and figuring out ratios based on the fact that he and I have totally different req_fuel values. His configs have been a tremendous help and guestimating a lot of things for my config. Also, Id like to publicly thank autotune . Do you think I should make the 20 psi my main goal instead of 24 tapering to 19 like my IA ecu did? I have been striving to reach the level of tune the IA chips provided with hopes of surpassing that tune using the meth injection and more ignition advance. Perhaps I can make just as much power with 20 psi and meth (lower MAT/110 octane equivalence) and ignition advance though? I added 5 to both the 40 and 160 dTPS areas. Will see how that goes. Those errant values in the VE table were just mess ups from the auto tune feature that I planned to fix at some point. 101 - 103 is the going range for atmosphere when the car is off so I went to 105 kPa for the "off below this pressure" feature for the N75. Will take the logs soon but I have no gas money until 034 refunds my ring gear and too long crank bolts RMA theyre getting tomorrow. Need money for food more than gas lol. This VEMS FW catastrophe will never stop haunting me. Still recovering from the money lost there.

One last thing, what the heck if my refDC values are 100% and I'm still not reaching the boost goal at higher RPMs? Havent logged it yet obviously but for instance I changed the refDC value for 6k rpms on that table to 100% to see if things move upward there. It was close to there already previously.

No, I think you can still make 24 psi tapering to 19 your goal, but there is no way in hell you will see 19 psi at 7500 or 8k RPM. First of all, I don't think the turbo will do it. Secondly, you will run out of fuel. Where you can accomplish something is with the meth injection and timing advance, but I really do think you will be limited by fuel in the upper RPM range. You will make usable power, but you will have to taper it off up top.

You may need a bit more than that in the dTPS/dt. You should be able to play with that easily on the fly though. Just watch your wideband while you poke at the throttle and make adjustments to that plot. You can even adjust it to some degree when you're parked.

Put 100% refDC everywhere and then tell us what it does. Make sure to get a log, and back off if it goes lean! If that doesn't have a big effect, then we should see what happens when you take your wastegate line off (or pinch it shut, depending on how you have it set up).

Sounds good. Im a little worried going 100% as I can't safely view the wideband displayed on my laptop to watch for lean conditions but I'll do my best. The local guy I thought could help Mr tune has a rip chip so there will be no ride alongs. I will for sure listen for the detonation to determine where the problem lies with the ignition. I'll be in touch

Just get any friend to sit in the passenger seat and show them what to look for. Or get any friend to drive the car while you watch. It's pretty easy... Third gear, full throttle, wheeeee, stop. Check log, repeat. After you do it enough you can start making changes without looking at logs for basic stuff but you basically need that few minutes to check what's going on every time.

I had a little time today after work so I took a log w/o meth and with meth. Keep in mind the first one chronologically is without meth injection and that I was more focussed on listening to the weird sound than keeping the pedal at 100%. I'll do a better one tomorrow. The second is far too rich from w/m being turned on. Needs tweaked like everything . Made some refDC changes made after the final log. I also made adjustments to the timing table (2 days ago I think it was) based on where the logs showed the table's activity during the weird rattle sound. My unprofessional conclusion is that it is not detonation and possibly my distributor (with metal gear installed) hitting a resonant frequency during certain RPM ranges. God it better be lol! I pulled 2.5 or 3 degrees timing out at the 3500-4500 range at 160-240 and back down to 160 kPa range and the sound is STILL there and seems unaffected by the ignition table. In my opinion the timing in those areas is already quite low or am I wrong? Its freaking weird. There seems to be great power and no wavering of it when the sound occurs. Although that could be because I think I read that during logging the knock retard table's function is disabled?? What option might I have to replace the hall sensor input as far as unrelated to cam and no likelihood of rattle ever? The meth injection didn't have an affect either and I thought for sure that would have a bearing on it. Im thinking about taking the hood off while I drive it one day to "observe" better. I have also messed with the dTPS table a bit as you can see in the logs. After my first hard pull on a highway area of road I came to a light and waited a minute and upon it turning green there was a puff of black smoke behind my car like a diesel. I came to another light and it did not happen again, or ever again after that for the remainder of the drive. Maybe it was blowby or CCV oil getting sucked in after coming close to doing just that after the high boost run. I don't get smoke anywhere during the pulls from the exhaust either.

turns out it was just a loose catalytic converter heat shield that got knocked loose during the last flywheel replacement job. I secured it better so the rattle is MUCH quieter now. Also returned the timing back up to the previous numbers. Id like to squeeze more out of the timing table as right now it feels marginally slower than my old IA chipset was up top. Can anyone comment on how much timing they are running at 5k to 7500 rpm WOT? K24's apply within, although I have a strong suspicion most of you went to better things long ago concerning turbos.

A new development.... I am now back to the drawing board concerning the cold air intake and refDC N75 table. I had to ditch the restrictive K&N Apollo filter system as it was choking the car big time. I threw something together using the massive chevy Tahoe K&N filter I used to run on the 5K and it doesn't really look any better but its gonna make the engine feel like it recovered from black lung over night. I hope it fixes the high RPM choking and when I ran just the old MAF with its mesh screens without the Apollo the car boosted WAAY high above the 25 PSI my gauge reads. That's a good indicator me thinks. Gotta redo the tables now

Lol that's good news. I've never heard of a filter so bad it was being that restrictive!

Glad to hear that your car is up and running! Interesting that that Apollo intake is so restrictive. Just out of curiosity how did you run the big chevy Tahoe air filter on the 5K? Was that with the stock airbox somehow?

Hah yeah it was quite unnatural looking on the 5k!! I bought the cheaper air filter I could find and cut the surrounding seal off and put it in the air box. Next I cut the box's cover with a hole saw where the OEM snorkel was and cold welded a 3" pvc piece in it so I could run some more piping from there to a remote location just forward of the passenger front wheel. I then attached the filter there but it was too close to the ground so I put the K&N drop-in filter back in the box and left the remote piping in.. The car came with the oils cooler bypassed and that's the ONLY reason I I had room in that area for the filter. I was able to put the old filter in the 200 with $8 in clamps and tubing. Thanks for the support guys. Anyone need a low cfm Apollo? Lol.

I was a little concerned yesterday. Had a huge detonation scare. I pulled all my plugs and found what looked like little craters in all of the tops of my pistons! I panicked but realized that the light from my flashlight might be making the craters look concave instead of possibly being physically convex. I took a length of plumber's thick sauder and zip tied a thick piece of paper towel on it and wiped the pistons with it to find that the craters were just pieces of either dirt or carbon that fell off somewhere from the w/m injection I just started using. Holy Christ I was ecstatic! My gear is the Apollo was not only too low to the ground like on the 5k but not filtering for shit so that gave me the steam to move on a new filter design today. Also I adopted Phil's ignition table as he left his as it was from Marc many moons ago with great results. It will be another 6 degrees more aggressive up top so that should satisfy my need for break-neck speed finally.

Its hard to believe just how freaking loud the turbo is on this car... It really grabs attention cuz it sounds like my car is going to blow apart hahaha

Is it really 6 degree's off?
that's kind of alot. like worrisome a lot.

Before you change timing, make sure the fuel map is 100% situated. Don't even touch timing yet. Make sure lambda is at the required amounts at EVERY single VE Cell.

Yeah I kinda feel like the kid who just discovered how great his model glue smells. after figuring out the filter problem I was ready to go balls out tomorrow with the timing but I realize now im asking for trouble by charging ahead like this. I'll take it slow with timing and check all the important fuel stuff first. Would hate for my car to go boom boom

KnockPhones are awesome.

Hmmmm. I've already got some nice studio headphones too !

Imagine my surprise when I found my throttle body unless hose half off with the hose clamp only appearing to be on near the viable top half. We shall see how my power is affected by that fix. I turned PID on and holy crap the car came to life! Not exaggerating

I suppose these deserve the time of day on the net. The new filter setup: the filter is three times as long as is visible.

Nice, post some more logs once you get things sorted.

Poor flywheel :(

Definitely Matt! Its my massively expensive memento now

Cool. Chris, do you prefer my logs that include my meth injection activated or deactivated? I tend to run it now as it makes me feel warm and fuzzy (safer) and also because it is my end goal to run it when this is all tweaked. I realized that my kPa settings were not representative of my goals and found I was running lower/comparable boost than/to the IA chipset so I set my peak level to 268 kPa which is 24.5 psi I guess by my google calculation lol. I should mention I run 93 octane on both my cars and probably something like 35% meth to water.

You really shouldn't need the meth on a k24, but it will let you eek out a few more hp with the added timing. It doesn't matter to me if you run the meth or not as far as looking at the logs is concerned. I can help you with fuel and making it run the way you want, get the right boost, idle, etc. I'm not comfortable messing with timing online though.

Why not a 50:50 mix?

This is one single pass with meth. Taper is ridiculous at the end of the rpm range. Seems to be out of my control as refDC is 100% at the end. Thanks in advance Chris! BTW I notice that when the boost starts its downward spiral, the MAT spikes from 4 to 5 degrees upward. Overspun turbo? If I reduce the boost just before this downward dive is it feasible that I could maintain higher boost further towards redline?

your anger is still focused in the wrong direction Julian. if you sneeze wrong those flywheels will strip teeth of the ring gears. ask Hank how he feels about the material they use.

Hey Marc, any chance you can look at my log? Thanks